A glass fiber which is an optical transmission medium, is obtained by the fiber drawing of a preform containing silica glass as the main ingredient, and the periphery of the glass fiber consisting of a core and a cladding is provided with a coating resin layer for protecting the glass fiber to manufacture an optical fiber. The coating resin layer, for example, comprises two layers which are a primary resin layer and a secondary resin layer. The outermost layer of the coating resin layer may comprise a colored layer (ink layer) for distinguishing optical fibers.
The manufactured optical fiber passes along a pass line guided by rollers or capstan rollers, and is finally wound on a bobbin. Although the coating resin layer of an optical fiber has insulating properties, the fiber is charged by friction with a roller or the like, and repulsive force or attractive force may act between a bobbin and the fiber to cause irregular winding.
Discharging an optical fiber by disposing a static eliminator on a pass line to prevent irregular winding is described in JP H4-357136 A. Preventing charging at the time of winding after the formation of a colored layer by adjusting water absorption and the amount of the remaining double bonds of a colored layer in specific ranges is described in JP 2001-48598 A.